Jennifer Aniston and Sandra Bullock 'best friends'

Jennifer Aniston and Sandra Bullock have reportedly become the "best of friends".

The 45-year-old star and the 49-year-old actress have struck up a close relationship after meeting at mutual pal Gwyneth Paltrow's house party and bonding over their previous painful divorces and past boyfriends.

A source told Us Magazine: "Jen and Sandra are new best friends forever. They're very excited about the new friendship."

The former 'Friends' beauty and the 'Gravity' star - who have both dated actor Tate Donovan, 50, in the past - have been spending a lot of time together ever since.

The source explained: "Sandra and Jen have a lot in common and enjoy each other's company. They have been having each other over for dinner regularly."

The new pals were rumored to be working with each other earlier this year after they were both linked to a comedy movie with Cameron Diaz, but the upcoming plans are yet to be confirmed.

Meanwhile, Jennifer - who was married to Brad Pitt from 2000 until 2005 - is currently engaged to Justin Theroux following their three-year relationship.

While, Sandra, on the other hand, has four-year-old son Louis - whom she adopted with ex-husband Jesse James - but raises him as a single-parent.